A Site Plan Review is required if trees are being removed from the property, unless the removal meets an exception in City Code Section 11-3-13.E.
A. Purpose and objective.
1. Purpose. Trees and woodlands are considered a valuable asset to the City of Cottage Grove. The City places a priority on protecting this asset and finds that it is in the best interests of the public to regulate the development and alteration of wooded areas within the City. The City also finds that a certain amount of tree removal is an inevitable consequence of the development process and seeks to establish comprehensive standards related to reasonable tree removal and preservation.
2. Objective. In order to achieve a realistic balance between tree protection and development, the City has established standards that with compliance and enforcement will:
a. Protect, preserve and enhance the integrity of the natural environment;
b. Allow for orderly development within wooded areas;
c. Minimize tree and wildlife habitat loss and maintain wildlife corridors;
d. Protect privacy by maintaining buffers between land uses;
e. Increase and maintain property values;
f. Prevent and reduce soil erosion and sedimentation;
g. Promote sound stormwater management practices;
h. Improve air quality;
i. Reduce noise pollution; and
j. Enhance energy conservation through natural insulation and shading.
B. Definitions: The following words, terms and phrases when used in this Chapter shall have the meaning ascribed to them in this Section except where the context clearly indicates a different meaning.
ACTIVELY DEVELOPING SUBDIVISION: A residential subdivision that has an approved tree preservation plan, and vacant platted lots controlled by a development company that is actively promoting, selling, or building residential units.
CONIFEROUS TREE: A wood plant which, at maturity, is at least twelve feet (12') or more in height, and which retains its green color year-round and does not drop its fronds or needles in the winter.
CRITICAL ROOT ZONE: An imaginary circle surrounding the tree trunk with a radius of one foot (1') per one inch (1") of trunk diameter, such that, for example, a twenty-inch (20") diameter tree has a critical root zone with a radius of twenty feet (20').
DBH: Diameter of a tree measured four and one-half feet (4 ½') above the ground.
DRIP LINE: The farthest distance away from the trunk of a tree that rain or dew will fall directly to the ground from the leaves or the branches of the tree.
HARDWOOD DECIDUOUS TREE: A tree of one (1) of the following species: ironwood, oak, maple (hard), walnut, hickory, birch, black cherry, hackberry, or locust.
HEALTHY TREE: A healthy tree has:
1. A live top (live crown) that is greater than one-third (1/3) the total tree height,
2. Newly dead branches that make up less than fifteen percent (15%) of the total crown,
3. Less than fifteen percent (15%) of the tree crown with missing branches,
4. Foliage that is dense throughout the live portion of the crown,
5. A tree trunk with open wounds that are less than one-third (1/3) the diameter of the tree, no wounds in contact with the ground, and no wounds that have soft, punky wood or other indication of decay.
LARGE WOODLAND TRACT: A wooded area greater than or equal to seven thousand five hundred (7,500) square feet of contiguous or nearly contiguous canopy cover.
QUALIFYING TREE: A healthy tree meeting one (1) of the following definitions: a hardwood deciduous tree at least six inches (6") DBH, a softwood deciduous tree at least eight inches (8") DBH, or a coniferous tree at least ten feet (10') in height, but no trees consisting of the following species: any tree on the Minnesota Department of Natural Resources invasive species list, ash, or elm.
SOFTWOOD DECIDUOUS TREE: A tree of one (1) of the following species: cottonwood, poplar, aspen, silver maple, basswood, or willow.
C. Prohibited tree removal. The removal of qualifying trees on any property by means of clear cutting or in a systematic removal method shall be prohibited, except in accordance with a City-approved tree preservation plan or agricultural management/harvest plan, or unless it is excepted pursuant to subsection E.
D. Allowable tree removal. The following table establishes the maximum percentage of existing qualifying inches on a project site that may be removed without mitigation. Mitigation according to the tree replacement schedule is required when removal surpasses this threshold.
Land Use | Permitted removal threshold (percent of existing qualifying inches) |
Residential <10 units/acre | 25% |
Residential >10 units/acre, Business/Commercial | 40% |
Industrial | 50% |
1. The following types of trees do not need to be included as part of the total computation of tree removals:
a. Trees determined by the City or the project arborist to be dead, dying, diseased, or seriously hazardous;
b. Trees that were planted as part of a commercial business such as a tree farm or nursery. The applicant shall provide evidence to support the finding that the trees were planted as part of a commercial business.
E. Exceptions. Tree removal is allowed without preservation plan in the following circumstances:
1. The removal of individual qualifying trees on a developed single-family residential lot that is not in a pending or actively developing subdivision.
2. The removal of shrubs, brush, buckthorn, and nonqualifying trees by a property owner.
3. The removal of trees seriously damaged by storms, other catastrophic events or disease, as verified by the City Forester.
4. The removal of trees with potential to cause serious damage as determined by the City Forester.
5. The removal of twenty-five (25) or fewer qualifying trees annually associated with agricultural or commercial horticultural use. Properties in active agricultural production of trees/tree farms shall have an agricultural management/harvest plan filed with the City for planned tree removal in excess of twenty-five (25) qualifying trees annually that shall include the following:
a. Legal description of property.
b. Crop/tree identification.
c. Acres to be managed.
d. Soil erosion control measures.
e. Removal staging plan.
6. The removal of twenty-five (25) or fewer trees.
F. Tree preservation plan. The tree preservation plan shall include separate plan sheets with the following information:
1. Contact information of applicants, property owners, developer/builder, and signature of the person preparing the plan, the certification, and employer or firm.
2. Delineation of the existing buildings, structures, or impervious surfaces situated on the site.
3. Delineation of the proposed buildings, structures, grading or impervious surfaces planned on the site.
4. Delineation of all areas to be graded and limits of land disturbance.
5. Graphic identification of all existing qualifying trees.
6. Graphic identification of all qualifying trees proposed to be removed within the construction area.
7. Tree protection plan as described below.
8. A listing of the total diameter inches of existing qualifying trees on the site.
9. A listing of the total diameter inches of healthy qualifying trees proposed to be removed.
10. Calculation of replacement trees required per the mitigation requirements this Chapter.
a. Coniferous tree calculation. Every two feet (2') in height of a removed qualifying coniferous tree is equal to one (1) qualifying inch.
11. Tree inventory prepared by a certified arborist that meets the following requirements:
a. Table listing each qualifying tree on the site and specifying its identification number (linked to a metal field tag placed on the tree’s trunk five feet (5') from grade); species; size (dbh in inches for deciduous trees and height in feet for coniferous trees); classification as hardwood, softwood, or coniferous per the definitions of this Section; and whether the tree is to be preserved or removed.
b. Exception. For sites containing a large woodland tract within which no qualifying trees will be disturbed, an alternative inventory meeting the following requirements may be provided:
(1) Trees within undisturbed large woodland tracts are not required to be inventoried individually. Instead, the area of the undisturbed tract may be measured in square feet (on site or by means of an aerial photo) and divided by sixty (60) to produce a proxy that shall be counted as the number of inches the tract contributes to the total qualifying inches.
(2) All qualifying trees located on the site but outside of an undisturbed large woodland tract shall be inventoried as described in (1) above.
(3) The site’s total existing qualifying inches shall be the sum of the inches contributed by undisturbed large woodland tracts and by qualifying trees outside the tract.
G. Mitigation.
1. For any development or site in which the number of qualifying inches removed exceeds the permitted removal threshold, the applicant shall mitigate the tree loss in one (1) of the following ways.
a. Planting replacement trees in appropriate areas within the development in accordance with the tree replacement schedule; or
b. Paying to the City a cash mitigation fee, based on the diameter inches of required replacement in accordance with the tree replacement schedule. The cash fee in lieu of required replacement inches shall be in accordance with the individualized calculation for the development or site and described fully in a development agreement or improvement agreement; payment shall be deposited into the public landscaping initiative fund prior to tree removal activities.
2. Landscaping credit. Replacement trees planted in accordance with a tree preservation plan and related mitigation shall be credited against City landscaping requirements.
3. Tree Replacement Schedule:
a. Quantity: Qualifying tree inches removed beyond the permitted thresholds shall be replaced at a rate of fifty percent (50%), equaling one (1) replacement caliper inch for two (2) removed diameter inches.
b. Size: Deciduous trees planted in mitigation of excessive tree loss shall have a minimum caliper of two and one-half inches (2 1/2") and coniferous trees shall be a minimum of six feet (6') tall.
c. Species: Coniferous trees or hardwood deciduous trees as defined and described in Section B are the only tree species permitted to be used as replacement trees. One (1) new conifer six feet (6') in height shall be credited as contributing two (2) caliper inches to the total of required replacement inches. Where ten (10) or more replacement trees are required, not more than thirty-three percent (33%) of the replacement trees shall be of the same species of tree. Applicants are encouraged to plant trees indigenous to the area. In no case shall a tree of a species listed on the DNR invasive species list be planted as a replacement tree.
4. Example calculation:
Total Existing Qualifying Inches | Permitted Removal Threshold | Inches Permitted to Be Removed | Inches Removed | Excess Inches Removed |
1500 | 50% | 750 | 1,000 | 250 |
Replacement Rate | Replacement Inches Required | Replacement Inch Credits | Replacement Trees (One Possible Combination) |
50% | 125 | Hardwood deciduous: 2.5" Coniferous: 2" | 30 hard wood deciduous and 25 coniferous |
H. Tree protection plan. The applicant shall implement the tree protection plan prior to and during any grading or construction activity. In addition, tree protection measures shall remain in place until all land disturbance and construction activity is terminated or until a request to remove the tree protection measures is made to, and approved by, the City.
1. The applicant will hire a project arborist that is a certified arborist or forester to assist with all facets of tree preservation on the site.
2. The applicant shall arrange for the City and project arborist to inspect the construction site prior to the beginning of grading to ensure that protective fencing and other protective measures are in place and installed correctly, if requested by the City. Minor encroachment, grading, trenching, filling, compaction, or change in soil chemistry may occur within the fenced areas protecting the critical root zone of the trees to be saved under the direct supervision of the project arborist.
3. Qualifying trees designated for preservation which are found to be diseased, or dying, or are not suited for location into the project may be removed without penalty based upon the written recommendation of the project arborist. Documentation of qualifying trees recommended for removal by project arborist must be provided to the City prior to removal of said trees.
4. If a qualifying tree that was intended to be preserved is removed without providing prior documentation to the City, the applicant shall mitigate the unplanned tree removal through replacement at a rate of one hundred percent (100%), that is, one (1) replacement caliper inch will be required for each one (1) diameter inch of a removed deciduous tree, and one (1) replacement foot shall be required for each one foot (1') of height of a removed coniferous tree. Alternatively, unplanned tree removal shall be mitigated by payment of a cash fee equivalent to the cost of the number of new trees this replacement rate would require, in accordance with the City Forester’s annual determination of the costs of new trees.
5. The City shall have the right to inspect the development and/or building site in order to determine compliance with the approved tree preservation plan. The City shall determine whether compliance with the tree protection plan has been met.
6. Required protective measures. The applicant shall complete all recommendations made by the project arborist, and shall implement the following measures to be utilized to protect qualifying trees:
a. No grade change, construction activity, or storage of materials shall occur within the drip line or critical root area of qualifying trees to be preserved.
b. Prevention of change in soil chemistry due to concrete washout and leakage or spillage of toxic materials, such as fuels or paints.
7. Warranty. Any replacement tree which is not alive or healthy, as determined by the City, or which subsequently dies, other than those damaged by storms or other acts of God, or diseased, unless caused by construction activity, within one (1) year after the date of project closure, shall be removed by the applicant and replaced with a new, healthy tree meeting the same minimum size requirements immediately after removal. The required landscaping letter of credit may be retained by the City and used to ensure the applicant conforms to this requirement.